Facebook and Microsoft are discussing an agreement that would significantly expand the search relationship the pair have shared for many years, said several people with knowledge of the situation.

According to those sources, that includes the possibility for the software giant’s Bing search service to mine anonimized data from consumer usage of the social networking site’s recently introduced Like buttons.

The Like button, which Facebook has been trying to proliferate around the Web, allows users to indicate an interest in a page with one click that then tells their Facebook friends.

While the deal is not closed and talks could end without result, such information might yield a treasure trove of insight for both search users and advertisers.

That’s because it represents search based on what people are actually interested in rather than just crunching massive amounts of information and muscling it into something useful.

And it would also presumably give Bing a little leg up on Google (GOOG), since data will be available on it that is not available on the search giant, made more important as Facebook’s information-generating audience grows ever larger.

But because of Facebook’s many privacy snafus, sources said that any expansion of the search relationship will never involve providing any information except that which users have agreed to make public.

AllThingsD by Writer

AllThingsD.com is a Web site devoted to news, analysis and opinion on technology, the Internet and media. But it is different from other sites in this space. It is a fusion of different media styles, different topics, different formats and different sources. Read more »